Exact Solutions of the Equilibrium Shape Equations in a General WLC Model for DNA Forms

In this letter,we are going to use a geometrical approach to describe the free energy of DNA structures.The exact solutions of the equilibrium shape equations in a general WLC model for DNA forms by using the Feoli's formalism [A.Feoli,et al.,Nucl.Phys.B 705(2005) 577] are studied.Then,the free energy of transition between Band Z-DNA is calculated in this formalism.

Generation of countless embedded trumpet-shaped chaotic attractors in two opposite directions from a new three-dimensional system with no equilibrium point

A new three-dimensional （3D） continuous autonomous system with one parameter and three quadratic terms is presented firstly in this paper. Countless embedded trumpet-shaped chaotic attractors in two opposite directions are generated from the system as time goes on. The basic dynamical behaviors of the strange chaotic system are investigated. Another more complex 3D system with the same capability of generating countless embedded trumpet-shaped chaotic attractors is also put forward.

STUDY OF THE EQUILIBRIUM HCP CRYSTAL SHAPE BY THE ISING MODEL

The Isin g model is used to investigate (0001), (10^-10), (10^-11) interfaces, etc. , for the hcp lattice. The system studied here have the nearest-neighbor (NN) and next-nearest-neighbor (NNN) pair interactions. The interface energy, interface phase transition at zero temperature and roughening temperature are used to analyse the properties of these interfaces. As a special case of the hcp crystals, we give the equilibrium shape of the He crystal at T=OK.

基于Python的托卡马克等离子体位形编辑器设计与实现

等离子体位形控制是等离子体实验控制的重要组成部分,设计满足放电要求的等离子体平衡位形是等离子体控制系统的重要功能之一。根据位形计算原理、中国聚变工程实验堆等离子体控制系统用户界面集成原理及用户界面需求,采用开源的Python语言及PyQt库,设计开发位形编辑器,用于等离子体期望位形设计和优化;并提供期望位形输入数据,供其集成使用。对主要模块进行复用,开发可独立运行的位形编辑器,能够灵活适用于不同的托卡马克装置。测试结果显示,该编辑器能满足单机运行的需求,同时消除了必须登录等离子体控制系统才可进行位形设计工作的弊端。

反兴奋剂教育的立法反思与规范形塑——基于中国高水平运动员及辅助人员反兴奋剂教育情况调查的实证研究

《反兴奋剂条例(修订草案)》新增了关于反兴奋剂教育的一系列规定。值此修法之际,评估反兴奋剂教育的实际效果,对于反兴奋剂教育规则的规范塑造尤为重要。这涉及探寻何种因素显著影响了反兴奋剂教育效果,以及基于对这些显著影响因素的考量,如何构建一个更加完善的反兴奋剂教育规则体系。对此,笔者进行了一项针对中国高水平运动员及辅助人员的反兴奋剂教育情况调查。研究发现,反兴奋剂教育活动的规格、时长、频次以及受访者的项目类型和学习意愿等因素对反兴奋剂教育效果起着显著作用。基于此,笔者提出应当从义务与权利规则整体均衡、规则设置考量要素系统均衡、规则内容构设动态均衡三个维度形塑反兴奋剂教育的法律规范,推动该领域规范供给的科学化、精细化,以确保在法治框架内贯彻落实习近平总书记关于反兴奋剂工作的重要指示精神。

Real Time Equilibrium Reconstruction Algorithm in EAST Tokamak

The EAST (HT-7U) superconducting tokamak is a national project of China on fusion research, with a capability of long-pulse (- 1000 s) operation. In order to realize a long-duration steady-state operation of EAST, some significant capability of real-time control is re-quired. It would be very crucial to obtain the current profile parameters and the plasma shapes in real time by a flexible control system. As those discharge parameters cannot be directly measured, so a current profile consistent with the magnetohydrodynamic equilibrium should be evaluated from external magnetic measurements, based on a linearized iterative least square method, which can meet the requirements of the measurements. The arithmetic that the EFIT (equilibrium fitting code) is used for reference will be given in this paper and the computational efforts are reduced by parametrizing the current profile linearly in terms of a number of physical parameters. In order to introduce this reconstruction algorithm clearly, the main hardware design will be listed also.

Plasma shape optimization for EAST tokamak using orthogonal method

It is necessary to reduce the currents of poloidal field(PF) coils as small as possible, during the static equilibrium design procedure of Experimental Advanced Superconductive Tokamak(EAST). The quasi-snowflake(QSF) divertor configuration is studied in this paper. Starting from a standard QSF plasma equilibrium, a new QSF equilibrium with 300 kA total plasma current is designed. In order to reduce the currents of PF6 and PF14, the influence of plasma shape on PF coil current distribution is analyzed. A fixed boundary equilibrium solver based on a non-rigid plasma model is used to calculate the flux distribution and PF coil current distribution. Then the plasma shape parameters are studied by the orthogonal method. According to the result, the plasma shape is redefined, and the calculated equilibrium shows that the currents of PF6 and PF14 are reduced by 3.592 kA and 2.773 kA, respectively.

Determination of the Stable Slope Configuration of Oval-Shaped Furrow Pits

The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle.The interaction of limit equilibrium slope angle,friction coefficient,cohesion and horizontal radius of oval-shaped furrow pits has been derived.The oval trumpet-like rock mass is homogeneous and elastic while only loaded by its dead weight.The interaction indicates that the deeper an oval-shaped furrow pit is excavated,the greater the limit equilibrium slope angle.Both the theory base for reducing stripping waste rock in an oval-shaped furrow pit and the basic way to determine the configuration of a stable slope were developed from the mentioned interaction.The theory includes the preceding principles of stability analysis of slopes.Compared with the configuration determined by traditional theory of slope stability,a great quantity of stripping waste rock can be reduced by that determined in this paper under stable conditions.

“借力式发展”:资本下乡背景下村企互动的均衡样态及其实现机制——基于鲁西南L村的案例研究

在资本下乡过程中村企互动均衡样态的分析概念“借力式发展”,是指村企双方通过借力彼此的身份与资源优势,撬动发展所需,在不断交换的基础上实现利益分配结构的均衡,进而建构一种双方互惠格局。案例研究表明,积极有为的村集体中介机制、“结构—行动”借力机制和互动平台的适时转变机制推动了村企之间“借力式发展”的有效运行。“借力式发展”在理论维度上有助于突破以零和博弈为假设的村企互动样态,在实践层面能够为村企在农村社会的均衡互动提供知识基础。

塔尔煤田Ⅱ区块露天矿外排土场边坡形态优化

为了解决露天煤矿外排土场边坡形态优化问题,基于逐水平形态优化理论,提出了外排土场边坡形态优化方法;以塔尔煤田Ⅱ区块露天矿外排土场边坡为工程背景,综合采用刚体极限平衡法与数值模拟技术,分析了原设计外排土场各帮边坡稳定性,对外排土场各帮边坡形态进行了优化,并分析了外排土场形态优化带来的经济效益。结果表明:外排土场各帮边坡+100 m水平设计平盘宽度为25 m,+120 m水平设计平盘宽度为20 m,新设计参数的外排土场比原设计参数的外排土场可多容纳9.16 Mm3的排弃物料,实现了在保证安全的前提下最大限度提高外排土场收容能力。

多策略融合改进的均衡优化算法及其应用

针对均衡优化(EO)算法寻优过程中存在兼顾全局探索和局部开发能力弱、寻优精度低、易陷入局部最优等问题,提出多策略融合改进的均衡优化算法(MEO)。首先,采用高破坏性多项式突变策略初始化种群,提高初始阶段解的质量,为全局寻优奠定基础;其次,提出差分变异的重构均衡池策略,丰富迭代过程中种群的多样性,增强算法规避局部最优的能力;同时,采用S型变换因子平衡算法的全局探索和局部开发能力;最后,引入动态螺旋搜索策略,扩大算法的搜索范围,提高算法的收敛精度和速度。仿真实验将MEO算法与标准EO算法以及其他元启发式算法在8个基准测试函数上进行寻优比较,实验结果与Wilcoxon秩和检验结果均表明,本文改进策略能提高EO算法的寻优精度、全局探索和局部开发的能力以及跳出局部最优的能力。另外,将MEO算法应用在无线传感器网络(WSN)覆盖优化中,实验结果表明,MEO算法可以显著提高WSN的覆盖率,降低节点的冗余度,使节点分布更均匀。

岬间砂质海岸平衡形态模型及其在华南海岸的应用

本文介绍了对数螺线、双曲线、抛物线三种岬间海湾平面平衡形态模型,并通过对比分析,表明抛物线为三种模型中较为理想的模型.根据抛物线模型的基本原理,本文提供了模型的可行性操作,并就抛物线模型对华南岬间海湾的应用展开了讨论.

华南海平面变化分析及海岸的响应

根据粤西及珠江口12个验潮站1953-997年的月均潮位资料,采用奇异谱(SSA)分析方法,预测了华南海平面的变化,并根据预测结果,采用Everts剖面积分法,以后江湾和水东湾为例,分析了华南海岸对海平面上升的响应。其结果表明,微小幅度的海平面上升就可造成岸线较大幅度的退缩。

二维沙质海滩剖面形态试验研究

海滩形态是近岸过程与海岸工程的一个重要研究内容,为探讨人工沙滩平衡剖面的形成及其形态特征和波浪作用下的滩面泥沙运动,从泥沙与波浪运动的相似规律出发,采用天然沙以正态整体模型进行二维沙质海滩的形态试验。试验证明人工沙质海滩在波浪作用一定时间之后,其剖面基本趋于一种平衡状态,沙源的向岸推移和向海下拉的情况也基本稳定。试验显示混合波的冲刷要大于单纯斜向波,单纯斜向波的冲刷大于单纯正向波,因此人工沙质海滩施工时应考虑到不同来波方向对剖面的影响。对比各个系列的整个人工沙质海滩剖面变化情况,可以看出整个沙滩剖面呈冲刷形态:从岸向海方向,在滩肩平台上形成一定的沙源堆积体;在滩肩缘到斜坡中部侵蚀最大,在斜坡下部侵蚀较小且向海呈逐渐减小趋势。

岬间海湾平面平衡形态研究进展

岬间海湾平面平衡形态规律的研究是砂质海岸稳定与演变研究的重要内容。简要回顾了岬间海湾平面形态规律的研究进展,着重介绍了海湾平衡形态的五个模型。通过评述平衡形态模型的优缺点,指出机理分析和经验拟合相结合应该为以后海湾平面平衡形态规律的研究发展方向,并论述了我国岬间砂质海湾平面平衡形态研究的重要意义。

露天矿内排土场堆叠过程中边坡形态优化

针对露天矿内排土场在堆叠过程中的边坡形态问题,以哈尔乌素露天矿内排土场为工程背景,应用刚体极限平衡软件定量分析了内排土场堆叠至不同高度时的边坡稳定性及其潜在滑坡模式,采用数值模拟软件FLAC3D对内排土场边坡进行模拟分析,揭示了内排土场边坡的变形破坏形式及其滑坡机理。结果表明:哈尔乌素露天矿内排土场的潜在滑坡模式及其稳定性主要受基底弱层的控制;优化后排弃至1025平盘时边坡角度为18°、排弃至1095平盘时边坡角度为17°、排弃至1165平盘时边坡角度为16°、排弃至1200平盘时边坡角度为16°;内排土场边坡的滑坡机理为基底赋存的弱层在排弃物料的自重作用下产生塑性屈服,其与排弃物内部产生的滑裂面贯通时,边坡岩体发生剪切破坏并沿内排土场基底弱层挤出。

金属氧化物表面与界面的第一性原理热力学:一个研究实例(英文)

通过第一性原理计算研究,能够揭示和阐明材料相关表面与界面热力学性质,这是通向纳米和界面材料设计自由的重要一步,即以理想性能为目标,科学设计制备工艺参数,针对性地调控材料微观结构。以SnO2纳米颗粒表面和原位内氧化制备获得的Ag?SnO2界面计算研究为例,系统介绍这一计算研究策略。基于缺陷热力学模型,构建不同环境温度和氧分压条件下所对应的热力学平衡状态的表面和界面结构模型,计算评估其相应性能。通过一系列的第一性原理能量学计算,进一步构建出平衡状态的表面与界面相图。这些相图能够充分描述制备和服役过程中,工况对材料表面和界面微观结构和相应性能的影响和作用关系。介绍和讨论如何应用这些相图理解和科学设计相应材料的制备工艺。

海滩平衡剖面形态研究进展

海滩剖面形态是近岸过程与海岸工程环境的一个重要研究内容，对其研究具有重要的理论意义和应用价值。在 Bruun-Dean 剖面模式的基础上，研究人员提出了许多新的海滩剖面形态模式。作者对近年来提出的各种平衡剖面模式进行了总结，认为加强泥沙动力学研究是解决理论模式与实际剖面形态偏离的关键。最后作者指出了研究我国岬湾间海滩剖面具有的重要意义。

单泡声致发光现象——气泡的稳定性

被水中驻波声压捕获在声压波腹的单个气泡,能周期地发出宽度50ps～140ps的光脉冲,这种现象称为单泡声致发光。稳定的单泡声致发光的参数主要由振荡形状稳定性、质量扩散平衡、组分的化学平衡和高的能量集聚等条件确定。文章将根据上述四条件对气泡的动力学稳定性作简单讨论。

Morphologies of epitaxial islands on a lattice-misfitted substrate

Under certain growth conditions for systems with a film/substrate lattice misfit, the deposited material is known to aggregate into island-like shapes. We have obtained an analytical expression of the total free energy, which consists of strain energy, surface energy and interfacial energy of a coherent island/substrate system, and the change of equilibrium aspect ratio versus the volume of the island and the misfit of lattices in the system, which provides a broad perspective on island behaviour. These then were used to study the equilibrium shapes of the system. The results show that in order to minimize the total free energy, a coherent island will have a particular height-to-width aspect ratio, called equilibrium aspect ratio, that is a function of the island volume and misfit. The aspect ratio is increased with increasing island volume at a fixed misfit, and with increasing misfit strain between the island and substrate at a fixed island volume. Moreover, the effect of misfit dislocation on the equilibrium shape of the island is also examined. The results obtained are in good agreement with experiment of observations and thus can serve as a basis for interpreting the experiments.